Purpose of this study is determined effects of different teaching approaches on programming skills. Therefore, the effect of three different types of activities prepared with Scratch on 423 sixth grade students' attitudes towards computer technologies, algorithmic thinking skills and reflective thinking skills on problem solving were investigated. Three IT teachers at the three schools, were asked to prepare and teach one of the three activities in their computer classes so that a different type of activity was provided at each school. The practical phase was carried out twice a week for seven weeks. A mixed method design was used with quantitative and qualitative components. Results showed that although the same programming tool and similar code blocks were used in the three applications, selected activities resulted in different effects on students. It was found that animation activities of the three types of activities had a positive effect on students' attitudes towards computer technologies. The mathematical and game preparation activities had positive effects on algorithmic thinking and reflective thinking skills for problem solving. The present study reveals the importance of "activity type," which is often neglected as a variable in studies investigating the different effects of block-based visual programming tools.